The present invention relates to a flat cable and a connector cooperating therewith for transmitting information signals in information processing apparatuses.
With increase in the number of signals to be processed in recent information processing apparatuses, use of so-called flat cables is increasing for transmitting the signals between various information processing apparatuses. Most of such flat cables and corresponding connectors are designed according to the SCSI (small computer system interface)-II protocol known also as FAST-SCSI prescribed by ANSI (American National Standard Institute), particularly with regard to the pin assignment. Thus, there is a need to design the flat cables and connectors in compliance with the SCSI-II protocol while minimizing crosstalk between the signal cables.
Conventionally, the flat cables have been designed such that signal cables for carrying signals and power cables for supplying the electric power have been disposed alternately for avoiding crosstalk between the signals. By disposing the signal cables and the power cables alternately in the flat cable, it is possible to minimize the adversary effect on the waveform of the signals transmitted along the signal cables. Thus, the connector provided at an end of such a flat cable also has a pin assignment such that the pins for the signal cables and the pins for the power cables are disposed alternately.
In the foregoing SCSI-II interface, on the other hand, it is prescribed such that two rows of pins are provided in the connector and such that the pins for signals are only in one of the foregoing two rows of the pins.
FIG. 1A shows the construction of a conventional connector cable 11A including a connector 12 and cooperating a cable assembly 15 designed according to the SCSI-II protocol, wherein the connector includes pins or contact elements disposed in two rows.
Referring to FIG. 1A, it will be noted that the connector 12 includes a contact part 13 and a cable interface part 14, wherein the contact part 13 includes contact elements for electric connection to a corresponding connector, while the cable interface part 14 is provided with two rows of terminals in electrical connection to the corresponding contact elements of the contact part 13, for connection of the cable assembly 15. The cable assembly 15, in turn, is formed of two flat cables 15a and 15b, and each cable forming the flat cables 15a and 15b is connected to a corresponding terminal by way of press contact achieved by connector housings 16a and 16b. It should be noted that each of the cables 15a and 15b extend in the direction of insertion of the connector cable 11A to a corresponding socket or connector.
FIG. 1B shows another conventional connector cable 11B formed of a connector 17 and a cable assembly 15. The connector 17 includes a contact part 18 and a cable interface part 19, wherein the contact part 18 includes contact elements for interconnection to a corresponding socket or connector. On the other hand, the cable interface part 19 has terminals in electrical connection to the contact elements in the contact part 18, for connection of the flat cables 15a and 15b. The individual cables forming the flat cables 15a and 15b are connected to corresponding cable terminals by way of press contact at a connector housing 20, and the flat cables 15a and 15b extend from both sides of the housing 20.
Thus, the foregoing conventional connector cables 11A and 11B have the feature that two flat cables 15a and 15b extend from the cable interface part 14 or 19. In any of the connector cables 11A and 11B, it is necessary to use one of the flat cables such as the flat cable 15a explicitly for carrying signals and the other flat cable 15b explicitly for carrying the electric power, in order to design the connector 12 or 17 in compliance with the pin assignment of the SCSI-II protocol.
In the foregoing connector 11A or 11B designed as such, it should be noted that the signal cables and the power cables are no longer disposed alternately in the flat cables 15a and 15b. Thus, there occurs a problem in that such conventional SCSI-II cable connectors are vulnerable to crosstalk of the signals in the flat cables.